20915681139950 has 12 divisors (see below), whose sum is σ = 38903166920400. Its totient is φ = 8366272455960.

The previous prime is 20915681139931. The next prime is 20915681140069. The reversal of 20915681139950 is 5993118651902.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20915681139950.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 209156811350 + ... + 209156811449.

It is an arithmetic number, because the mean of its divisors is an integer number (3241930576700).

Almost surely, 2^{20915681139950} is an apocalyptic number.

20915681139950 is a deficient number, since it is larger than the sum of its proper divisors (17987485780450).

20915681139950 is a wasteful number, since it uses less digits than its factorization.

20915681139950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418313622811 (or 418313622806 counting only the distinct ones).

The product of its (nonzero) digits is 5248800, while the sum is 59.

The spelling of 20915681139950 in words is "twenty trillion, nine hundred fifteen billion, six hundred eighty-one million, one hundred thirty-nine thousand, nine hundred fifty".